This is a Swedish cake recipe; I got it from a dear friend who made it at several parties during college and always got rave reviews. Now I'm the one who gets all the credit when I make it : ) My family loves it; I play the "guess-the-secret-ingredient" game (the vinegar) and no one ever has... though they've guessed everything from peanut butter to cheese! I love it because it's relatively "healthy" (no dairy, no eggs, low-fat), while it's still amazingly moist and chocolaty and dense. (You can make it even lower fat if you use only 1/4 C oil and sub. 1/2 C applesauce).